#include <sys/poll.h>

sys/poll.h

This file is intended to be compatible with the traditional poll.h.

15 macros · 1 struct · 1 typedef · 1 function

Requestable events. If poll(2) finds any of these set, they are copied to revents on return.

#define POLLIN 0x0001

any readable data available

#define POLLPRI 0x0002

OOB/Urgent readable data

#define POLLOUT 0x0004

file descriptor is writeable

#define POLLRDNORM 0x0040

non-OOB/URG data available

#define POLLWRNORM POLLOUT

no write type differentiation

#define POLLRDBAND 0x0080

OOB/Urgent readable data

#define POLLWRBAND 0x0100

OOB/Urgent data can be written

FreeBSD extensions: polling on a regular file might return one of these events (currently only supported on local filesystems).

#define POLLEXTEND 0x0200

file may have been extended

#define POLLATTRIB 0x0400

file attributes may have changed

#define POLLNLINK 0x0800

(un)link/rename may have happened

#define POLLWRITE 0x1000

file's contents may have changed

These events are set if they occur regardless of whether they were requested.

#define POLLERR 0x0008

some poll error occurred

#define POLLHUP 0x0010

file descriptor was "hung up"

#define POLLNVAL 0x0020

requested events "invalid"

#define POLLSTANDARD (POLLIN|POLLPRI|POLLOUT|POLLRDNORM|POLLRDBAND|
	                 POLLWRBAND|POLLERR|POLLHUP|POLLNVAL)

size 8, align 4

typedef unsigned int nfds_t

__DARWIN_ALIAS_C(poll)
extern int poll(struct pollfd *, nfds_t, int)

This is defined here (instead of <poll.h>) because this is where traditional SVR4 code will look to find it.

man page · March 18, 2015

poll(2) — synchronous I/O multiplexing